It is known to provide an anchoring device which is suitable for use in anchoring a railway rail-fastening clip to a fail foundation, the device including (when in the orientation in which it is used) a part which is to lie above the foundation and is formed with an upper wall section and two opposite upstanding wall sections joined to opposite extremities of the upper wall section, these wall sections partially defining a substantially horizontal passageway.
Such anchoring devices, made by casting metal, are disclosed in Belgian Patent No. 897,056 and U.S. Pat. No. 3,326,466, for example, with the latter also disclosing devices of this type made by bending sheet metal. In the anchoring devices shown in the drawings in these patents, there is no electrically insulating material in the passageways, which in each case receive a single limb of a rail clip made by bending a metal bar of circular cross-section. Thus, the clip makes direct contact with the anchoring device. It is, however, stated in the said U.S. patent that a sleeve of plastics material such as nylon could be fitted into the passageway and the limb of the clip could be driven into the sleeve. The purpose of the sleeve is not stated, nor is its shape, but a person skilled in the art would assume that it is of circular cross-section and intended for use as an anti-wear liner.